The overall goal of this proposal is to continue the ongoing PROSPECTIVE STUDY of high-risk adolescents and young adults from the COGA study to enhance our knowledge about genetic, behavioral and environmental risk factors that contribute to the development of heavy drinking, alcohol related problems, alcohol use disorders (AUDs), and related psychiatric conditions. The COGA study is unique in gathering important information from multiple domains across generations of well characterized, multi-ethnic families collected nationally. Data include psychiatric, electrophysiological, neuropsychological, environmental, and genetic factors gathered prospectively from families at high risk for AUDs and from comparison families. Parallel measures for these domains were gathered previously on the original proband parents and other biological relatives in addition to the adolescents and young adults who are the focus of our ongoing work. Data from the parental generation have been successfully used to identify numerous risk factors for heavier drinking and associated problems and have helped to identify genes related directiy to the risk for AUDs and associated characteristics (highest quantities consumed, craving, levels of response to alcohol). Our work has also identified genes that contribute to externalizing behaviors measured both through structured interviews and electrophysiological profiles. Thus, the proposed work presents the unique opportunity to observe the ways in which genetic variants, electrophysiological endophenotypes and behavioral characteristics identified In one generation may operate, in conjunction with the environment, during the developmental phases of adolescence and eariy adulthood of the next generation. This cross generational information may help identify additional behavioral and environmental characteristics associated with gene variation and other markers of risk, which in turn would enhance our understanding of a broader array of risk factors for AUDs.